Seventeen years of transient monitoring experience in French PWR units

Transient bookkeeping is the procedure implemented by Electricite de France to meet the regulatory requirements (checking whether the design mechanical margins are respected under operating conditions). It enables damage due to main primary system equipment fatigue to be evaluated. The currently procedure, by means of some provisions and precautions (complete transient file, qualified personnel) gives appreciable results that can be used for a variety of purposes (determining harmfulness, lifetime project). However, it is very restrictive and does not enable specific load areas to be followed up. The implementation of the SYSFAC process will remedy this disadvantage thanks to the use of fatigue measuring devices; it will also keep a close check on the damage caused by main primary system fatigue in general. (author). 2 refs., 4 figs., 2 tabs